Handheld multichannel air-displacement pipettes are well known, and have been commonplace in laboratory settings for decades. Such pipettes are particularly useful for fast, convenient transfer of liquid samples between microtubes and multi-well plates, for example. Generally, multichannel pipettes have multiple nozzles arranged in one or two evenly-spaced rows, and the nozzles are configured to receive disposable pipette tips similar or identical to tips used on single-channel handheld pipettes. See U.S. Pat. No. 4,779,467, which is hereby incorporated by reference as though set forth in full, for an example of a traditional multichannel pipette configuration.
Because multichannel pipettes are handled by laboratory personnel so frequently, and are often used for long uninterrupted periods of time, ergonomic considerations are paramount. However, in order to maintain accuracy and reliability, some tradeoffs have often been made. Multichannel pipettes are often uncomfortably large and heavy, with precision metal parts used to ensure accuracy, consistency, and durability. Not only are such metal parts heavy, they tend to be expensive to manufacture as a result of the labor-intensive processes necessary to assemble them.
Channel-to-channel consistency is an important quality for multichannel pipettes. Unintended variation may result in experimental anomalies or other poor results. Accordingly, as noted above, multichannel pipettes made with bulky, heavy parts have proven to be reliable scientific tools. However, in some cases, this weight can result in fatigue over long periods of usage.
Accordingly, a need exists for an adjustable multichannel pipette that avoids the limitations of the prior art. Such a pipette would include advantageous features, such as a compact design that is reliable, accurate, capable of precise fluid measurement, yet lightweight. These characteristics and features are achieved while retaining ease of assembly and service, and providing excellent channel-to-channel volume measurement consistency and performance.